The invention proposes a protective casing for an electronic appliance.
The invention proposes more particularly a protective casing for an electronic appliance of the type which has a shell in which there is produced an opening closed off by a body made from transparent material with a generally flat shape.
The invention also proposes an electronic appliance having such a casing.
Such protective casings are for example used for mobile telephones of the Global System for Mobile Communications, or GSM type.
The protective casing naturally protects the components of the electronic appliance such as a keypad and switches whose activation modifies the electrical state of a control circuit. In the case of a mobile telephone, the protective casing must in particular also protect a display screen which provides the interface between the appliance and the user.
To do this, the casing generally has an opening or window closed off by a body made from transparent material with a generally flat shape. The display screen is then arranged inside the casing opposite the opening.
In some cases, the body made from transparent material has special optical properties such as a magnifying effect which then improves the legibility of the information displayed on the display screen.
The body made from transparent material must be sufficiently strong to protect the display screen against impacts or scratches which may be due to rubbing of the electronic appliance against other objects, for example metallic keys, when it is placed inside a purse.
Thus the dimensions of the body made from transparent material, in particular its thickness, as well as its characteristics, in particular the hardness of its external face, are determined so as to resist impacts and scratches.
To do this, it is known that a body made from plastics material can be used, whose thickness is around 2 to 5 mm and whose external face is covered with an anti-scratch protective cladding which increases the surface hardness of the external face of the body.
The fixing of the transparent body to the casing is generally carried out by adhesive bonding of a peripheral area of the transparent body, which is oriented towards the inside of the casing, on a peripheral area of the opening which is advantageously situated inside the casing so that the external face of the casing and the external face of the transparent body are substantially aligned or flush.
In this case, glue is visible from the outside of the casing through the plastic body. This is detrimental to the aesthetic appearance of the telephone.
So as to conceal the glue, a decorative cladding can be placed on the external face of the body made from transparent material before this face is covered with the protective cladding.
However, when the protective cladding is not sufficiently strong to protect the body made from transparent material, the decorative cladding may be scratched.
The distance which separates the display screen and the decorative cladding, which is around several millimeters, causes an impression of distancing of the screen towards the inside of the casing. This impression is detrimental to the overall appearance of the electronic appliance.
In addition, when light external to the casing illuminates the latter in a direction which is not perpendicular to the overall plane of the body made from transparent material, the protective cladding causes the formation of shadows on the screen, which interfere with the reading of the information supplied by the screen.
To remedy these problems, it is known that the decorative cladding can be interposed between the fixing area of the transparent body and the fixing glue.
However, it is not possible to concomitantly place the protective cladding and the decorative cladding on their respective areas situated on opposite faces of the transparent screen.
So that the decorative cladding provides a positive aesthetic effect, it must be placed on a flat surface. However, the surface evenness of the internal face of the transparent body is not always sufficient. This causes irregularities in the cladding which are visible to the user.
When the thickness of the transparent body is around a few millimeters, the user can see through the side faces of the body, which is detrimental to the overall appearance of the electronic appliance.
In order to resolve these problems, the invention proposes a protective casing for an electronic appliance of the type which has a shell in which there is produced an opening closed off by a body made from transparent material with a generally flat shape, of the type in which at least one internal peripheral annular area for fixing the transparent body is fixed to an area opposite the periphery of the opening by fixing and/or positioning means with the interposing of a first decorative cladding between the peripheral area for fixing the transparent body and the fixing and/or positioning means, characterized in that the peripheral fixing area is inclined with respect to the overall plane of the transparent body.
According to other characteristics of the invention:
the inclined peripheral fixing area extends over the whole of the periphery of the transparent body;
the substantially flat external face of the transparent body is coated at least partially with a second cladding, notably a protective cladding, for example non-scratch, for the external face of the transparent body;
the fixing and/or positioning means include a layer of glue;
the fixing and/or positioning means include at least one insert, and the first cladding at least partially masks the insert;
the angle of inclination of the peripheral fixing area is around 30xc2x0 with respect to the overall plane of the transparent body.
The invention also proposes a method of manufacturing a protective casing of the type described previously, characterized in that: the insert is produced by molding a first material in a first cavity delimited by the impressions of two matrices of a first mold; then the insert is transferred into a second cavity, delimited by the impressions of two matrices of a second mold, into which a second transparent material is injected so as to produce the transparent body by molding the second material on the insert.
According to other characteristics of the method:
when the insert is being produced, the first decorative cladding is deposited on the area of the insert complementary to the peripheral fixing area of the transparent body, by transferring the first decorative cladding which belongs to a film which extends in the cavity of the first mold;
when the transparent body is molded, the second cladding is deposited on at least part of the external face of the body by transfer of the second cladding which belongs to a film which extends in the cavity of the second mold.
The invention also proposes a tool for manufacturing a protective casing of the type which has:
a first mold consisting of a first bottom matrix and a first top matrix each having an impression so as to delimit a first cavity in which the insert is produced, and
a second mold consisting of a second bottom matrix and a second top matrix each having an impression so as to delimit a second cavity into which the insert on which the transparent body is molded is transferred, characterized in that the first bottom matrix and the second bottom matrix each have an identical impression.
According to other characteristics of the tool:
the first and second bottom matrices are able to move with respect to the first and second top matrices;
the first and second top matrices are produced as a common top matrix having two impressions, the first and second bottom matrices are produced as a common bottom matrix having two impressions and in that a common matrix is mounted so as to pivot about an axis orthogonal to the parting plane of the molds so that its pivoting through 180xc2x0 allows the alternating cooperation of each of these two impressions with each of the impressions of the other two matrices.